NEW YORK (Reuters Health) - Paternal messenger RNAs are transferred to oocytes at fertilization along with the haploid male genome, investigators report in the May 13th issue of Nature. This suggests that spermatozoal RNA is important in very early zygotic development, senior author Dr. Stephen A. Krawetz, at Wayne State University in Detroit, said in an interview with Reuters Health.
His group’s findings could be used to “help understand male factor idiopathic infertility based on the presence or absence of normal mRNAs” in spermatozoa, he said. Another application could be “adding back RNA to improve cloning efficiency” for producing embryonic stem cells after somatic-cell nuclear transfer.
He and his associates had previously identified about 2800 different mRNAs in normal sperm. Of those believed to be important in early development, six were present in sperm and testes but not in oocytes.
Using the zona-free hamster egg/human sperm penetration assay, the team identified two transcripts delivered by spermatozoa and present in zygotes but not in oocytes, those encoding protamine-2 and clusterin.
Loss of mRNA may indicate exposure to noxious agents, Dr. Krawetz said. For this reason, his group is submitting grants to develop screening techniques to identify toxic exposures.
“Spermatogenesis is a process of continual self renewal and differentiation,” he explained, “so if we look at a new population of cells every 60 to 80 days, and if a man has been acutely exposed, we’d expect to see a drop-off effect.”
If this works, he added, “we hope to better guide people exposed to toxic agents, with the ultimate goal of maximizing the chances of a healthy child.”
Source: Nature 2004;429:154. [ Google search on this article ]
MeSH Headings:Genetic Techniques: Growth and Embryonic Development: Investigative Techniques: Nuclear Proteins: Physiological Processes: Protamines: Reproduction Techniques: Cloning, Organism: Analytical, Diagnostic and Therapeutic Techniques and Equipment: Biological SciencesCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
